Expense Account required to be completed when Changed AP Addition to Post Status

Hi,

When I go to Prepare Mass Additions window to change the Status to post to an Addition associated with an AP Invoice the System requires the Entry of an EXPENSE ACCOUNT

Why is required to enter this account and how the system will use it?

Is it the Depreciation Expense Account? If yes, why is not defaulting the Depreciation Expense Account setup for the Asset Category selected in the PO/Supplier Invoice?

Regards,

cv